Sutter, J U and Homann, U and Thiel, G (2000) Ca(2)+-stimulated exocytosis in maize coleoptile cells. Plant Cell, 12 (7). pp. 1127-1136. ISSN 1040-4651Full text not available in this repository. (Request a copy from the Strathclyde author)
Changes in membrane capacitance (C(m)) after photolysis of the caged Ca(2)+ compound dimethoxynitrophenamine were studied in protoplasts from maize coleoptiles. Changes in C(m) values resulting from increased concentrations of free Ca(2)+ in the cytoplasm ([Ca(2)+](cyt)) were interpreted as representing changes in [Ca(2)+](cyt)-sensitive exocytosis and endocytosis. A continuous increase in [Ca(2)+](cyt) resulted in a sigmoidal increase in C(m) values with a half-maximal concentration at approximately 1 microM. The steep increase in C(m) values was followed by a variable slow phase in changing C(m) values. When [Ca(2)+](cyt) increased at a rate of 0.6 micromol L(-)(1) sec(-)(1), the initial steep increase in C(m) values lasted approximately 5 to 10 sec. During this time, protoplasts increased in surface area by approximately 2.5%. The biphasic dynamics of [Ca(2)+](cyt)-stimulated increases in C(m) values can be described by a kinetic model containing two pools of vesicles with two [Ca(2)+](cyt)-sensitive steps in the exocytotic pathway.
|Keywords:||membrane capacitance, photolysis, dimethoxynitrophenamine, Plant culture|
|Subjects:||Agriculture > Plant culture|
|Department:||Faculty of Science > Physics|
|Depositing user:||Pure Administrator|
|Date Deposited:||12 May 2012 10:48|
|Last modified:||11 Nov 2016 04:05|